Page Type Page Type: Mountain/Rock
Location Lat/Lon: 44.59279°N / 114.47617°W
Additional Information County: Custer/Lemhi
Activities Activities: Hiking
Seasons Season: Summer, Fall
Additional Information Elevation: 10340 ft / 3152 m
Sign the Climber's Log


South Twin at 10,340 ft. is the second highest summit in the Salmon River Mountains of Idaho and sits between White Mountain (10,442 ft.), the highest peak in the range, and North Tiwn (10,196 ft.) another of the highest summits. When viewed from Challis, Idaho South Twin appears to be the highest of the three but this is only because of the angle it is viewed at. It really is only 98 ft. lower than White Mountain though.
South Twin from White MountainSouth Twin from White Mountain.

The peak is a loose pile of rust colored talus when viewed from the South. When seen from the North it shares the whiteish hue of its neighbor, White Mountain.
Looking up from the Lookout RoadTalus

Twin Peaks LookoutThe Twin Peaks Fire Lookout.
This mountain is on the border of the Frank Church Wilderness as well as the boundary of Custer and Lemhi Counties. The most unique feature about this peak is the fire lookout and helipad atop its summit. At 10,340 ft. it is the highest active fire lookout in the Pacific Northwest and was built in 1913. (Here is a link with some cool historical pictures of the lookout.) The road leading to the lookout is also one of the highest roads in Idaho. Because of the road it is only a class 1 hike. The walk to the top is pleasant and the view from the top is absolutely amazing taking in everything from Mount Borah to the South, to the Bighorn Crags in the North and everything in between. In fact seven major mountain ranges (Pioneer, Boulder, White Cloud, Sawtooth, Salmon River, Beaverhead, Lemhi, and Lost River) are visible from its summit, all of them among Idaho’s highest and wildest.
Sunset on South TwinAlpenglow

Getting There

The Guards of Sleeping Deer RoadThe infamous guards.
From Challis take highway 93 East (towards Salmon) and turn left on Clinic Road. This will intersect with Challis Creek Road after curving around the town’s medical clinic and assisted living center. Turn Right on Challis Creek Road which will eventually enter the Challis National Forest and turn to dirt. This road will split and the left fork will take you to the Challis Creek Lakes. The right fork will be labeled as Sleeping Deer Road and will take you up Bear Creek Canyon towards the pass between North and South Twin. Beyond the pass the road will continue for 24 miles into the heart of the Frank Church Wilderness, eventually ending near Sleeping Deer Mountain. Continue up Sleeping Deer road and eventually you will come to some houses.
White Mountain MapMap
Just before the houses the road enters a pasture where a herd of horses and pack mules are kept. They like to stand on the road so you’ll probably need to coax them out of the way. At the edge of the pasture the road is gated to keep the animals in. Open and pass through the gate and remember to close it as soon as you’re through. Just beyond this the road splits again. Stay on Sleeping Deer Road which at this point has become a narrow two-track road. The farther up the road you go the better it will get though. Here it begins to parallel Bear Creek as it heads towards the 9,183 ft Twin Peaks Pass. Just before you get to the pass there will be some abandoned cabins where the road will split again. The left fork it the one that least to the lookout atop South Twin.

This is a very narrow road with room enough only to park or turn around at the switchbacks. There is no room for error as the drop-off on the downhill side can be pretty scary.

Depending on your vehicle you may wish to park where the road splits and walk up the road to the summit. If you’ve got a high clearance outfit you could continue up to the summit or at least to the first major switchback and walk the remaining 500 vertical ft. up the road.
Twin Peaks Lookout RoadLookout Road

Red Tape

Be aware that the lookout road is narrow and rough. While is 4WD is not essential it is a good idea. High clearance, though, is a must. Just pray you don't meet someone coming the other way.
Frank Church SunsetAmazing sunset from Twin Peaks pass.

Also be advised that the forest on West side of the Twin Peaks and White Mountain burned recently and can be subject to flash floods and other rapidly changing conditions.

Also, as with all wilderness areas, motorized travel is restricted in the Frank Church Wilderness. You shouldn’t need to worry about that though since you’re coming to climb. Remember, pack it in, pack it out.

No permits of any kind are required.



There are several good camping spots along Bear Creek. There is one established site with a table and fire ring near the cabins where the road splits. If you continue up the Sleeping Deer Road to the pass there is a large area established on the wilderness boundary suitable for camping. This area has several fire rings and a VERY primitive toilet.[img:527011:aligncenter:medium:Amazing sunset from Twin Peaks pass.]

External Links

Salmon-Challis National Forest

The Idaho Outdoors Forum is where you can talk to others interested in Idaho's mountains.

This is the website for Tom Lopez'sIdaho: A Climbing Guide, the premier guide to Idaho's mountains.

Some info about the Frank Church-River of No Return Wilderness

Some info about the Twin Peaks Lookout.



Children refers to the set of objects that logically fall under a given object. For example, the Aconcagua mountain page is a child of the 'Aconcagua Group' and the 'Seven Summits.' The Aconcagua mountain itself has many routes, photos, and trip reports as children.